Coupling loop



Feb. 16, 1943. D. G. cLlFFoRD COUPLING LOOP INVENTOR c?. 24F/raza www ATTORNEY Filed Aug. 13, 1941 Patented F eb. 16, 1943 COUPLING LOOP David G. Cliord, Montclair, N. J., assignor to Westinghouse Electric s Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application August 13, 1941, Serial No. 406,599

(Cl. 25o-27.5)

17 Claims.

This invention relates to electron discharge devices, and particularly to discharge devices of the type incorporating hollow cavity resonators.

The type of'electron discharge devices alluded to above is a comparatively recent development in the art, and from a general aspect comprises essentially two spaced hollow circuit members within which elds, comprising standing electromagnetic oscillations are adapted to be set up by the passage of a beam or stream of electrons therethrough. The said members act as and are accordingly referred to as resonators. They are usually built into the tube structure, comprise one electrode of the tube, and provide an area be-.

tween them which is eld free, but through which the electrons pass in their travel from the rst to vthe second said resonators. The electrons likewise pass completely through the elds of the resonators, completing such passage through each preferably within the period of one half cycle or less of the operating resonant frequency of the conducting resonant members. As the electron beam passes through the rst resonator, a sinusoidal component corresponding to the electrical oscillations existing within the resonator is impressed on the beam of electrons and produces a modulation of velocity or density of the electrons. The modulation, Whether of velocity or density, causes the electrons to collect in clusters periodically and the second resonator is so disposed as to absorb energy from the electrons as they pass through it. y

Provision may be made, as by a circuit coupling means with the rst resonator, for exciting the internal oscillations thereof. This may be by an external oscillator of suitable character to introduce an applied energy, or may be by a feedback from the second resonator, thereby employing a portion of the derived energy. Likewise, a circuit coupling means is provided for transmission externally of the derived energy.from the second resonator, as to an antenna. For any of these purposes, a means is employed which projects physically into the magnetic eld of the internal oscillations of the resonator, and accordingly, whether for feed-back purposes, for supplying externally established oscillation, or for deriving energy for an output circuit or device, said means will be herein generically denominated a coupling device.

Coupling means for resonators heretofore employed have been practically nothing more than a loop of wire o'r the like with the loop portion projecting into the resonator, an example of which may be seen in the patent of W. W. Hansen et al., No, 2,227,376 of Dec. 31, 1940, and wherein one leg of the loop has to pass from the inside to the outside of the vacuum chamber with a vacuum-tight seal. Such `a construction results in the device having its characteristics, whether they be good, bad or indifferent, deflnitely fixed by the sealing-in of the loop. The relative position of the loop, Whether oriented precisely at right angles to the magnetic eld or more nearly parallel thereto materially alters the effect of energy upon orsupplied to 'and by such loop. Similarly, marked differences in operation are obtainable by more or less projection of the loop into the resonator eld. Use of the loop as a feed-back coupling requires diierent setting thereof than when used for other purposes, such as for promulgation of the derived oscillations upon and from an antenna.

For a most effective and versatile construction of discharge device, therefore, it becomes important to provide a structure permitting orientation, and advancement or retraction of the loop, and provision of means for accomplishing this desideratum constitutes one object of the present invention.

Another object of the present invention is to provide for the orientation and advancement and retraction without in any way aiecting the vacuum seal of the discharge device.

A further object of the present invention is to provide for complete removal and replacement or substitution for the coupler of said coupling means.

Yet another object of the present invention is to provide for proper location and orientation of the coupler of said coupling means by visual indication associated therewith.

Still further objects Will appear to those skilled in the art as the description progresses, both by direct statement thereof and by implication from the conter.

In the accompanying drawing, wherein like numerals of reference indicate similar parts throughout the several views, and wherein a preferred physical embodiment of the invention is disclosed by Way of example;

Figure 1 is a sectional elevation of an electron discharge device of the character indicated with my improved coupling means incorporated thereof Fig. 2, for illustrating a slug-type of coupling means.

In the speciilc embodiment of the invention illustrated in said drawing, the reference numeral III designates in general a cylindrical container or envelope of a suitable material, such as copper, steel or other metal which' forms in its interior two resonator chambers for convenience herein designated as the ilrst resonator I I and second resonator I2, the ilrst resonator being situated nearest to the cathode (not shown) from which electrons emanate. Since the specific structure of cathode. grids, collector, and other usual parts are known in the art land do not primarily concern the present invention, they have not been disclosed in detail, but are to be considered as present in their proper places. Sufiice it to say that the envelope is evacuated, provides said resonators as part of the evacuated space with means for tuning the resonators to the same frequency as by providing end wall sections I3, I2 which are ilexible, enabling grids at an attenuated part to be adjusted in spacing. A beam of electrons is drawn from the cathode, passes through the attenuated openings of the resonators and th'e field-free space I4 between the resonators and thence to the collector at the other end portion of the device. As the beam of electrons passes through the first resonator II, a sinusoidal component is impressed on the beam which instigates a bunching of the electrons that becomes eifective to maximum degree in the second resonator I2 wh'ere the energy is absorbed for useful purposes, and referred to herein as derived energy.

Each resonator is preferably provided with two coupling means I5, I5, the inner ends of which project into the interior of the resonator through the peripheral wall of the container III in a substantially radial direction. At the exterior of the container, one coupling means I5 of the first resonator may h'ave suitable connection, as by loop Il, with one of the coupling means I5 of the other or second resonator by which the aforementioned feed-back of oscillations is obtained from the second resonator to the ilrst.

The companion coupling means I5 in the first resonator may be connected, if desired, to an external source of oscillation (not shown) or other modulating influence. Thus by one or the other or both' of the companion coupling means in the ilrst resonator, a sinusoidal component is impressed on the beam of electrons passing through that resonator.

The companion coupling means I5 to the one above referred to for feed-back in thesecond resonator, is for output purposes and transmits the derived energy to the exterior for appropriate use.

The preferred construction of coupling means I5 is shown more particularly in Figures 2 and 3. A projecting and threaded neck I1 with its interior passage I8 opening into the resonator ch'amber, is provided on the cylindrical wall of container I0. This neck is shown herein as separately formed from the container and welded in an opening thereof made for the purpose of receiving the inner end of said neck,the joint being vacuum tight and thus constituting the neck an integral part of the container. Next the outer end of said neck the passage I8 is enlarged and receives a thimble I9 therein, the inner end of which substantially nts the passage, is seated against and welded or soldered to a shoulder 20 in the passage to-also provide a vacuum tight Joint. The outer end of the thimble projects from said neck and has its entire peripheral Y marginal end tapered to a feather edge 2l.

` A glass or other ceramic tube 22 is provided oi a generally reentrant shape, such that the outer end portionl flares outwardly and then baci:--

wardly to provide an apron-like cylindrical outer portion 22 the edge of which is sealed to the feather edge 2| of the thimble I8. The inner body portionof tube 22 is considerably longer than the apron-like portion and is reentrant with respect thereto', passing through said apron-like portion, through the thimble I8 and neck I1 and a distance into the resonator. 'This inner 'endof the tube 22 within the resonator is closed. as by rounded end 2l.

It will accordingly be seen that a vacuum-tight resonator chamber is maintained around the reentrant portion of the tube and within the apron portion thereof with its seal to the thimble and vacuum tight mounting of both the thimble and neck. Access to the interior of said reentrant portion of the tube is available from the exterior, thereby forming an outwardly opening pocket projecting physically into but sealed with respect to the resonator chamber. Consequently a coupler or other instrumentality may be inserted, manipulated, removed or replaced at will with respect to the tube and as far within the resonator as permitted by the closed end of the tube, without disturbing the vacuum seal of the Y resonator.

For economy and eectiveness, said glass or ceramic tube 22 is preferably fabricated as an entity of graded glass, utilizing an inner end section 25 of quartz glass (having coefficient of expansion of 5) both for its strength and resistance to deleterious effects of heat and for its quality of readily passing the micro-wave energy. The outer section 28 which includes the apronlike portion 23,.is preferably of a character which will make an effective seal with the feather edge 2| of the thimble. For this purpose this section 25 of the tube may be of borosilicate glass (having coefilcient of expansion of 33) and effectively sealing with a thimble of` copper. Intermediate sections 21 and 28 of the tube between the borosilicate and quartz sections, may then be of glass having intermediate ratings of coefficients of expansion, for instance a glass known in the trade as '715A0 with a coeillcient of expansion of 21 used next to the borosilicate glass, and a number 707GS1 glass having a coefficient of expansion of i4 used between the rst-mentioned intermediate section and the quartz glass end section 25.

The particular coupler exemplified in Figure 2 is of coaxial loop type. Its construction comprises a metallic conductor tube 29 having an outside diameter less than the inside diameter of the ceramic tube 22 so as to be slidable and rotatable therein. Within the conductor tube 29 is a coaxial rod conductor 30 held in position by occasionaiinsulators within the conductor tube, such as glass beads 3|. The outer end of the rod conductor projects from the tube conductor as shown in Figure l, and an exterior loop 32 may be there provided for radio wave coupling purposes, said loop having one end physically and electrically fast with respect to the rod and its other end fast with respect to the tube conductor.

At the inner end of the tube and rod conductors, is provided, in the presentl illustration, a hairpin-shaped loop 32, which, as a convenient mode of fabrication, may be a thinned integral end projecting longitudinally from the rod, bent back into parallelism at approximately a midpart of its length with the turned back extremity engaging and welded or soldered to the inner wall of the tube conductor. The two legs of the loop denne a plane, and for maximum effect with respect to the electromagnetic field .of the resonator, said plane should be transverse to the circular dimension or iield plane of the resonator. As the angle of orientation of the plane oi.' the loop approaches coincidence with the ileld plane of the resonator, interception of the resonator field lessens and coupling therefore becomes weaker. Also coupling is strengthened or weakened at will by more or less insertion of the loop into the resonator, this longitudinal movement also obtaining a tuning eilect by change of phase, frequency and amplitude of oscillation due to position and orientation change or due to the greater, or less coupling distance from one resonator to the other through external loop connection IS when withdrawing the loops from or projecting them further into the resonators.

Other coupling means, such as slug couplers, as shown in Figure 4 may be used in place oi the coaxial lead construction above described. A slug coupler 33 as shown in said gure may comprise simply a metal rod of substantially the diameter of the aforementioned tube conductor and inserted and withdrawn at will with respect to the ceramic tube 22. No matter which type of coupler is employed, however, it will be now clear that the coupler is removable and adjustable without in any Way affecting the vacuum or vacuum seal of the resonator.

For mounting, rotating and longitudinally adjusting :the coupler, the external threads on neck il engage with threads of an adjusting collar li thereon, on the outside o! which is a knurled ridge 35 or other means for conveniently manipulating the same. Next the outer end of this collar, overlapping the same peripherally, is an inverted cup-shaped head 3S also provided at its outside with a knurled ridge 3l therearound and provided with a central boss 32B through which the coupler is mounted, as by use of a lateral set-screw 39 in the boss. The said head 3E, where it overlaps the collar, may have a plurality of studs 1.0, 4i projecting radially inward adapted to have a sliding iit in a circumferential groove ft2 in the outside surface of the collar. One of the studs1 as lli, may have a winged or other head G3 by which the stud may be manipulated conveniently for tightening it in the groove and retaining the head against rotation with respect to the collar. On the outside of the collar is a scale M which will both show longitudinal and rotational position of setting of the head and coupler by relation to a double pointer 45 projecting into proximity to the scale from a xed attachment on the casing iii.

Since the various details of construction, as well as the precise relation and functioning of parts are subject to variation and change without departing from the inventive concept or scope of the invention, it is intended that all matter contained in the specification or illustrated in the drawing, shall be interpreted as exemplary and not in a limiting sense. It is also to be understood that the following claims are intended to cover all ofthe generic and specic features of the invention herein shown and described and all statments of the scope of the invention herein set forth as a matter of language which might be said to fall therebetween. t5

I claim:

1. An electron discharge device comprising an evacuated hollow body resonator, a pocket structure vacuum-sealed to said resonator and having aclosed end projecting intothe resonator and having an outwardly directed exterior open end. and a rotatable coupler slldably insertable in said pocket structure through said open end tor positioning the inner end of said coupler physically within the resonator and movable and removable with the vacuum-seal of the resonator retained unimpaired.

2. An electron discharge device comprising an evacuated hollow body resonator, a pocket formation therefor for reception from the exterior of an instrumentality an end of which is to be inserted into the confines of said resonator, said pocket formation comprising a reentrant tube having its outside portion providing an apronlike rim bounding a circular space and its reentrant portion extending through said space and past said rim and closed at its protruding end, and means vacuum-sealing said rim to said resonator with said protruding end constituting an outwardly open pocket inserted within the resonator.

3. An electron discharge device comprising an evacuated hollow body resonator, a. pocket formation vacuum-sealed with respect to the resonator body and having a closed end projecting into the resonator and having an outwardly directed exterior open end, a rotatable coupler slidably insertable in said pocket formation through said open end for positioning the inner end of said coupler physically within the resonator and movable and removable with the vacnum-seal of the resonator retained uniinpaired, and external means for rotating said coupler.

4. An electron discharge device comprising an evacuated hollow body resonator, a pocket formation therefor Vfor reception from the exterior of an instrumentality an end of which is to be inserted into the confines of said resonator, said pocket formation comprising a reentrant tube having its outside portion providing an apronlike rim bounding a circular Space and its reentrant portion extending through said space and past said rim and closed at its protruding end, means for vacuum-sealing said rim to said resonator with said protruding end constituting an outwardly open pocket inserted Within the resonator, and said reentrant tube being formed of sections of graded glass with the closed end of quartz glass.

5. An electron discharge device comprising an evacuated hollow body resonator, a tube transverse to and projecting into said resonator and vacuum sealed thereto, the inwardly projecting end of said tube being closed and the outwardly directed end being open, a rotatable coupler slidably insertable in said enclosure through said open end for positioning the inner end of said coupler physically Within the resonator and movable and removable with the vacuum-seal of the resonator retained unimpaired, and external means for sliding said coupler.

6. An electron discharge device comprising a sealed container, a hollow neck protruding from said container, a reentrant tube having its inner end closed and projecting into said container through said neck and having its outer end forming a turned-back apron-like rim, and means for `sealing said rim with respect to said neck whereby a vacuum-seal around said tube and within said container is maintained around outwardly opening pocket formation established in said container by said inwardly projecting and closed end of the tube.

` 7. An electron discharge device comprising an evacuated hollow body resonator, a rotatable coupler slidably insertable in said resonator with the inner end of said coupler physically within the resonator and movable and removable with the vacuum-seal of the resonator retained unimpaired, and means for both rotating and sliding said coupler.

8. An electron discharge device comprising a sealed container,y a hollow neck protruding from said container, a reentrant tube having its inner end closed and projecting into said container through said neck and having its outer end forming a turned-back apron-like rim, means for sealing said rim with respect to said neck Whereby a-vacuum-seal around said tube and within said container is maintained around outwardly opening pocket formation established in said container by said inwardly projecting and closed end of the tube, a coupler insertable in said outwardly opening pocket, and means exterior of said tube for supporting said coupler in optimum position.

9. An electron discharge device comprising an evacuated hollow body resonator, a tube vacuumsealed, next one end thereof to the resonator and closed at its other end and projecting into the resonator with its outwardly ldirected open end exterior vto the resonator, a rotatable coupler slidably insertable in said tube through said open end for positioning the inner end of said coupler physically within the resonator and movable and removable with the vacuum-seal of the resonator retained unimpaired, external means for rotating said coupler, and means for visually indicating the degree of rotation of said coupler.

10. An electron discharge device comprising an evacuated hollow body resonator, a tube vacuum-sealed next one end thereof to the resonator and .closed at its other end and projecting into the resonator with its outwardly directed open end exterior to the resonator, a rotatable coupler slidably insertable in said tube through said open end positioning the inner end of said coupler physically within the resonator and movable and removable with the vacuum-seal of the resonator retained unimpaired, external means for sliding said coupler, and means for visually indicating the degree of sliding of said coupler.

11. An electron discharge device comprising a sealed container, a hollow neck protruding from said container, .a reentrant tube having its inner end closed and projecting into said container through said neck and having its outer end forming a turned-back apron-like rim, means sealing said rim with respect to said neck whereby a vacy uum-seal around said tube and within said conment with said neck supporting said coupler in optimum position.

12. An electron discharge device comprising an evacuated hollow body resonator, a tube vacuumsealed at its outside to said resonator and having a closed end projecting into the resonator and having an outwardly directed exterior open end,

- a rotatable coupler slidably insertable in said tube through said open end positioning the inner end of said coupler physically within the resonator and movable and removable with the vacuumseal of the resonator retained unimpaired, means for both rotating and sliding said coupler, and means for indicating simultaneously both the degree of rotation and degree of sliding of said coupler.

13. An electron discharge device comprising an evacuated hollow body resonator. a rotatable and longitudinally slidable coupler having ajhairpin shaped loop at its inner end physically within the resonator and movable both longitudinally and rotatably with the vacuum-seal of the resonator retained unimpaired.

14. An electron discharge device comprising an `evacuated hollow 'body resonator, a rotatable and longitudinally slidable coupler having a hairpin shaped loop at its inner end physically within the resonator and movable both longitudinally and rotatably with the vacuum-seal of the resonator retained unimpaired, and means exterior of said resonator supporting said coupler in optimum position.

15. An electron discharge device comprising a plurality of evacuated hollow body resonators, a plurality of couplers having loops at their inner ends, and means mounting said loops both rotatably and longitudinally movable for varying relationship of any loop with respect to its position in the resonator and with respect -to any other loop at inner ends of other couplers.

16. In combination, a hollow body internally subject to energy oscillations, a coupling means therefrom for energy therein comprising a pocket structure, vacuum sealed to said hollow body, said pocket structure being closed at, one end and transparent next said closed end to said energy oscillations, said closedend projectlnginto the hollow body and having an outwardly directed open end, and a coupler movable with respect to said pocket structure and insertable substantially to the closed end thereof so as to be physically within the hollow body and capable of insertion and manipulation therein while the vacuum seal of the hollow body remains unimpaired.

17. A coupling means for high frequency wave energy of a charac-ter capable of propagation in hollow bodies and through space, comprising a 'pocket structure closed at one end and transparent thereat to said high frequency wave energy and insulative to electric current flow in the material of which said end is composed, a mounting means supporting said pocket structure, said pocket structure opening outwardly through and having its edge sealed to the said mounting means, and a coupler of electrically conductive material normally in said pocket structure movable and removable with respect thereto and having a part normally situated in proximity to the said closed transparent end of the pocket structure for effecting high frequency wave energy transfer through the said closed transparent end.

DAVID G. CLIFFORD. 

